1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/skbuff.h>
 3#include <linux/slab.h>
 4#include <linux/netdevice.h>
 5#include <net/gro_cells.h>
 6
 7struct gro_cell {
 8	struct sk_buff_head	napi_skbs;
 9	struct napi_struct	napi;
10};
11
12int gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb)
13{
14	struct net_device *dev = skb->dev;
15	struct gro_cell *cell;
16
17	if (!gcells->cells || skb_cloned(skb) || netif_elide_gro(dev))
18		return netif_rx(skb);
19
20	cell = this_cpu_ptr(gcells->cells);
21
22	if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
23		atomic_long_inc(&dev->rx_dropped);
24		kfree_skb(skb);
25		return NET_RX_DROP;
26	}
27
28	__skb_queue_tail(&cell->napi_skbs, skb);
29	if (skb_queue_len(&cell->napi_skbs) == 1)
30		napi_schedule(&cell->napi);
31	return NET_RX_SUCCESS;
32}
33EXPORT_SYMBOL(gro_cells_receive);
34
35/* called under BH context */
36static int gro_cell_poll(struct napi_struct *napi, int budget)
37{
38	struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
39	struct sk_buff *skb;
40	int work_done = 0;
41
42	while (work_done < budget) {
43		skb = __skb_dequeue(&cell->napi_skbs);
44		if (!skb)
45			break;
46		napi_gro_receive(napi, skb);
47		work_done++;
48	}
49
50	if (work_done < budget)
51		napi_complete_done(napi, work_done);
52	return work_done;
53}
54
55int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
56{
57	int i;
58
59	gcells->cells = alloc_percpu(struct gro_cell);
60	if (!gcells->cells)
61		return -ENOMEM;
62
63	for_each_possible_cpu(i) {
64		struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
65
66		__skb_queue_head_init(&cell->napi_skbs);
67
68		set_bit(NAPI_STATE_NO_BUSY_POLL, &cell->napi.state);
69
70		netif_napi_add(dev, &cell->napi, gro_cell_poll,
71			       NAPI_POLL_WEIGHT);
72		napi_enable(&cell->napi);
73	}
74	return 0;
75}
76EXPORT_SYMBOL(gro_cells_init);
77
78void gro_cells_destroy(struct gro_cells *gcells)
79{
80	int i;
81
82	if (!gcells->cells)
83		return;
84	for_each_possible_cpu(i) {
85		struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
86
87		netif_napi_del(&cell->napi);
88		__skb_queue_purge(&cell->napi_skbs);
89	}
90	free_percpu(gcells->cells);
91	gcells->cells = NULL;
92}
93EXPORT_SYMBOL(gro_cells_destroy);